Beware The Frozen Heart
by Scarlett the Squiddy
Summary: {HiJack/ Hiccup x Jack Frost Frozen AU} As children, Hiccup and his older sister, Eira, were incredibly close, but one day, Hiccup found himself shut out of his sisters life for thirteen years, their father dying in the tenth year, until the day of Eira's coronation, but Hiccup has been locked up in a castle for far too long, and seeing all the happiness, he wanted freedom.
1. The heart is not so easily changed

**Thank you for clicking this fanfic! I hope you enjoy it, okay first off, just a quick briefing on who the main characters in this are,  
Elsa- My OC, Eira Haddock  
Anna- Hiccup Horrendous Haddock III  
Hans- Astrid Hofferson  
Kristoff- Jack Frost  
Sven- Jamie Bennet  
Olaf- Toothless  
That's just the main explanation, so there is no confusion {I hope}**

_Disclaimer;; I do not own or claim to own How to Train Your Dragon, Rise of the Guardians or Frozen, thank you. I own Eira and that is it._

"Born of cold and winter air,  
And mountain rain combining,  
This icy force both foul and fair,  
Has a frozen heart worth mining,"

Jack heard the faint call of the familiar song of the usual ice miners of the kingdom of Berk. He followed it eagerly, knowing that they would find the best ice as usual.

"So cut through the heart, cold and clear,  
Strike for love and strike for fear,  
See the beauty, sharp and sheer,  
Split the ice apart!  
And break the frozen heart..."

Jack laughed a little and ran after the miners, carrying the heavy metal tool in his hand, followed by his eager friend and reindeer, Jamie.

"Hyup!"  
"Ho!"  
"Watch your step!"  
"Let it go!"

The miners around him grabbed their blocks from the water and Jack attempted to pick his small one up, only finding that he couldn't get a grip on it. He frowned a little and tried again.

"Hyup!"  
"Ho!"  
"Watch your step!"  
"Let it go!"

The other workers began collecting up their substantial piles of ice, and Jack watched them enviously, shivering from the slight cold.

"Beautiful!"  
"Powerful!"  
"Dangerous!"  
"Cold!"  
"Ice has a magic, can't be controlled.  
Stronger than one! Stronger than ten!  
Stronger than a hundred men!"  
"Hyup!"

Jack attempted still to fish his small block out of the water, it was getting darker and he began to worry that if he didnt get it out soon, he would have to leave empty handed.

"Born of cold and winter air  
And mountain rain combining!  
This icy force both foul and fair  
Has a frozen heart worth mining!"

Suddenly the block toppled over Jack, knocking him to the ground but causing him to smile proudly and begin to try to move it.

"Cut through the heart, cold and clear!  
Strike for love and strike for fear!  
There's beauty and there's danger here  
Split the ice apart!  
Beware the frozen heart..."

Jack had just loaded his block onto his small sled when the final line of the song caught in his ears. It gave him an odd sense of foreboding, and made him shiver lightly. He tried to ignore it and giggled softly.  
"C'mon Jamie!" He called to the young reindeer, leaping onto the sleigh.

He never did manage to fully shake off that odd feeling though...

Meanwhile, in the center of the kingdom, the great Berk, there was a castle. It stood tall and proud, surrounded by a busy, bustling town, however, by this time, it was deep night and most citizens were long asleep, except for one... A small, dark headed, frecklefaced boy.  
"Eira! Psst!" A young Prince Hiccup whispered, poking his sleeping older sister in the back. "Eira, wake up, wake up, wake up! You're snoring like Daddy!"  
Hiccup was referring to their father, King Stoick the vast of Berk, a large man with a ginger badger of a beard, a massive appetite and a tiny brain to go with it.  
"Hiccup go back to sleep already..." Murmured Eira, burying her face in her pillow.  
"Eira I just can't! The sky's awake, so I'm awake! So we have to play..." Hiccup whined, nuzzling Eira like the dragons he was so obsessed with.  
"You're acting like a dragon again you silly, go play by yourself..." She mumbled, shoving Hiccup out of her bed and straight into the pile of blankets on the floor.  
Hiccup rubbed his head a little, before his freckled face lit up. He crawled back up onto the bed, and giggled.  
"Do you wanna build a snowman?" He asked in a quiet tone.  
His sister smiled and pulled herself out of bed quickly, straightening up her hair. Standing up, you could see she was quite small, but taller than her brother, and dressed in a small blue nightgown. Her hair fell halfway down her back and was a black color, with highlighted whites. People always asked if she was born with it or cursed, and she always told them that it was real, but no one apart from her family knew how it came to be real. Eira had been the unlucky child to be born with ice powers, they were small when she was a baby but as she became a toddler and then a child, they grew. Her brother seemed to adore it, however, so she used them frequently.  
"Come on fishbone!" Eira called to her brother as she entered the great ballroom.  
"Do the magic! Do the magic!" Hiccup cried happily and Eira formed a small dragon in the palm of her hand, drawing a small 'Wow...' from her brother.  
"Ready?" She asked and when her brother nodded, she split it, and sent snow particles flying into the sky, and they began to fall, coating the ballroom floor in a thin blanket of snow.  
"Hey Hic, watch this!" Eira called, stamping her foot down onto the ballroom floor, spreading an icy layer on the floor, and skating around it happily.  
Hiccup then started to roll a snowball and the two of them started to make a snowman, which soon, thanks to Hiccup, turned into a snow dragon. Specifically, a snow Night Fury, the most mysterious dragon type in the land. Little was known about them except their looks, the fact that they eat fish and have retractable teeth. Hiccup and Eira's ancestor, Hiccup Horrendous Haddock II was the only person who ever documented seeing one, eating a pile of raw fish, giving Hiccup dreams of meeting dragons, hence why he turned the concept of snowman to dragon. They smoothed down the edges and Eira hid behind the dragon, giggling.  
"Hi, I'm Toothless and I like eating fish!" She said in a pretend low voice.  
"But Eira he has teeth!" Hiccup said stubbornly.  
Eira wooshed away the teeth quickly and Hiccup giggled.  
"I love you Toothless!" He squealed, going to sit on the dragon.  
"C'mon fish bone!" Eira called, pulling Hiccup up a small snow slope that had formed.  
They slid down it together, both screaming and giggling.  
"Look at me I'm flying Eira!" He called, before crashing into a snow bank.  
Hiccup quickly recovered, and began to jump from snow pile, to snow pile.  
"Hang on!" Eira called, laughing, as her brother jumped from pile to a sudden pile that Eira created to stop him falling.  
"Catch me!" He giggled  
"I gotcha!"  
"Again again!"  
"Wait slow down!" Eira called, worried, when she suddenly slipped and lost her footing on the slippery ice.  
Her brother, however, hadn't seen her fall and leaped off of the pile.  
"Look at me Eira! I'm a dragon!" He called, suddenly falling.  
"HICCUP!" Eira screamed, shooting out her hand to try to create a pile, but instead, to her dismay, she saw her beam had hit her brother right in the head.  
"Hiccup?" She whimpered, as her brother landed limply on the floor.  
She approached him, and held him in her arms, she shook him a little. He didnt move. She felt tears welling up in her eyes and was soon screaming at the top of her lungs.  
"PAPPA! PAPPA!" She cried, the room beginning to freeze up, the columns frosting over as she got more and more agitated. "You're okay Hiccup... I got you..."  
Suddenly the door flew open and a bewildered looking Stoick burst through.  
"Eira... What have you done?" He asked, shocked. "This is getting out of hand!"  
"It was an accident!" Eira cried to her father. "I'm sorry Hiccup..." She whimpered at her brother.  
"How is he?" He asked, worried.  
"He won't wake up Pappa... He's so cold..." Eira whimpered.  
Stoick got a determined look in his eye and he turned around, and walked back towards the door.  
"I know where we have to go."  
Stoick fetched a map from the library and soon, the three of them, bundled onto one horse, began riding through the forest, Eira leaving a trail of ice behind her as they rode.  
Jack was just riding on his sleigh, wooping at Jamie, travelling through the forest, when he saw the horse fly past. He looked at the ice trail in confusion, running a hand through his spiky white hair.  
"Ice?" He asked, touching the frost.  
He left his sleigh where it was and leapt straight onto his reindeer.  
"Faster Jamie!" He called to his reindeer, when they came to a mass of boulders, surrounding a clearing. The two of them hid behind one and waited.  
The king and his children got off of their horse, and made their way to the middle of the clearing. Eira held onto his leg, while Hiccup was held in his arms.  
"Please! Help!" Stoick began. "My son-"  
He couldn't finish what he was saying. His voice cracked.

Suddenly, the rocks rolled away, and out came elves, yetis, walking eggs and small hummingbird like creatures, followed by four of the most renowned creatures in the land, one of which popped up right next to Jack and Jamie. She looked like a feathered fairy, with peacock colored feathers from head to foot as she floated, her expression as bright as the colors on herself. Her name was Toothiana. The other three were named Aster Bunnymund, Sanderson Mansnoozie and their leader, Nicholas St. North. Bunnymund was a tall creature, over six foot tall, with grey blue fur, and swirling patterns, with a boomerang hanging at his side and a grumpy expression. Sanderson, or Sandy, was, on the contrary, very short, with golden sands flowing around him, he had a warm smile on his face. Nicholas St. North, their leader, was a medium height, stout man with almost no hair, but a bushy white beard to make up for it and dressed in a deep red coat with black trimmings.  
A flutter of, " It's the king!" passed through the ranks of the watching creatures.  
Jack felt a shocked expression grace hs face, not noticing the one next to him.  
"Wait... Is that... The guardians?!" He gasped, his eyes flying wide open.  
"Please shhh dears! I'm trying to listen!" Toothiana suddenly whispered, causing Jack to pull a nervous grin at her, as Jamie flashed his reindeer teeth toward her.  
"Oh how cute you are, with your perfect white teeth! I bet you don't have a family... I'm gonna keep you two!" She said, in a motherly tone.  
Meanwhile, North had approached Stoick and his children.  
"Your majesty." He began in a thick Russian accent, bowing. "Born with the powers or cursed?" He asked, causing Stoick to slam a fist down on a rock angrily.  
"You think I'd let anyone curse my daughter!" He began, red faced, but then remembered that he still needed their help. "Born of course, and they're getting stronger." He finished awkwardly, coughing slightly.  
North pressed a hand to Hiccup's head gently, and nodded slightly.  
"You were lucky it wasn't his heart." North started gravely. "The heart is not so easily changed, but the head can be persuaded." He finished, examining the boy once more.  
"Please... Anything just save my son..." Stoick begged, showing his caring side for once.  
North just nodded again, and pulled a glowing strand from his forehead, which turned into an image of Hiccup and Eira playing together.  
"We will remove all magic, even memories of magic, to be safe, but don't worry, I'll leave the fun." He said softly, transforming the images into something that seemed more realistic, with forests, snowstorms and sleds. "He will be okay." He said simply, seeing a relieved expression make its way onto the King's face, as he placed the memories back.  
Eira then piped up.  
"But Hic won't remember I have powers anymore?" Eira said sadly and nervously.  
"Eira that way, you can't harm him any more..." Stoick said bluntly and harshly, taking her hand and starting to lead her away.  
However, North grabbed her other hand and took it firmly, leading her away from her father.  
"Listen to me, Eira." North began, casting a blue silhouette up into the sky. "Your power will only grow! There is beauty in it," Eira felt herself gasp as she saw the beautiful patterns flying from the hands of the beautiful shadow,  
"but also great danger!" The sky suddenly flared red, causing her to scuttle back to her father.  
"You must learn to control it! Fear will be your enemy!" He finished as the silhouette was engulfed by the red light, and Eira hid her face in her fathers jacket.  
"No!" Stoick boomed, stamping his foot. "I will protect her! She can learn to control it..." He insisted. "'Til then... We will lock up the gates, fire some of the useless staff, don't allow her near anyone, keep her powers locked away from everyone... Especially Hiccup..." He decided.  
"No Daddy!" Eira gasped, but North lay a hand on her shoulder.  
"Eira, it is for the best that you stay away from Hiccup..." He explained, and Eira could do nothing but nod slowly and sadly.

**Thank you and please review ouo**


	2. Do you wanna build a snowman

**Yes I just sat and wrote this right after posting, I had a flair of inspiration that I couldn't ignore so here is chapter two.  
Sorry about the fact that Jack isn't really in it at all yet, but I need to build up the rest of the story first :3**

_Disclaimer; I do not own How to Train Your Dragon, Rise of the Guardians or Frozen._

Hiccup woke up, by himself early in the morning, just like any normal day, but his head felt fuzzy, as if he had been up late, but he remembered going straight to sleep. It confused him but he sat up and stretched.  
"Eira you awake?" He called, blinking his eyes open, focusing on the empty space where his sisters bed used to reside.  
He, panicked, leapt out of bed and sprinted into the corridor, still dressed in his pyjamas.  
"Eira where are you?" He called. "Eira?"  
Suddenly, he turned into the throne room, and approached his father in a panicked run.  
"-es get rid of them too, they're no use to us. Oh, and them the-"  
"Pappa! Pappa! Where's Eira?" Hiccup cut off his father, pulling on his arm nervously.  
"Oh good morning Hiccup!" Stoick beamed, before his face fell a little. "Eira decided to move rooms."  
"But why?" Hiccup asked sadly, his face breaking his fathers heart. "It's grown up stuff Hiccup... I need to talk to you son."  
"What is it?" He asked innocently.  
"Hiccup we're shutting the gates..." Stoick said sadly. "I don't know when we can reopen them."  
"Why?" Hiccup asked, his voice squeaking. "What about my friends?"  
"You'll have to make do, I'm sorry son, it's grown up stuff..." Stoick said, causing Hiccup to walk off slowly.  
"Your sister is in the room with the ice patterned door. The one you always said was pretty." Stoick told him sadly.  
Hiccup merely nodded and wandered off, back into the warmly carpeted corridor. Hiccup was never that popular, but he had had friends for a time. He figured now, that he would no longer receive a choice in the matter, and it saddened him greatly. He approached his sisters room, and tried to open the door. It was locked. This was strange, Hiccup thought, frowning a little. His sister had never been locked anywhere, or locked anything. He knocked on the door a few time.  
"Eira?" He called  
No response.  
"Eira are you in there?" He tried, unsure.  
No response.  
"They're shutting the gates... Pappa says he can't open them anymore. He won't tell me why." Hiccup told her with a sigh, slumping against the door.  
"I know." Came a forced response from Eira.  
"What are we going to do?" He asked sadly, but received no response from his sister at all.

Weeks passed, and Hiccup saw next to nothing of his sister. Stolen glimpses as she locked herself back in her room were all he could catch and it made him feel like crying. He didn't understand why she had suddenly shut him out, just like that. It saddened, confused and angered the young boy. He found himself wandering the castle, pretending to be a dragon, and trying to avoid the ice colored door. But one day, it snowed, and Hiccup found he couldn't keep away any longer. He ran excitedly to her room, and knocked on the door rhythmically.  
"Hey Eira! It's snowing! Do you wanna build a snowman? C'mon! It looks amazing, let's go play!" He started, starring expectantly, but receiving no response. "Come on Eira, I don't see anything of you anymore, come out of there!I mean it's like you got taken away by some dragon or a hawk or something. Eira?"  
The boy still received no response.  
"We always used to be best buds, we were each others bestest friends, but we aren't anymore, you've shut me out, I wish you would tell me why!" He exclaimed angrily, before sighing and leaning up on his tip toes. "Do you wanna build a snowman? You know, it doesn't have to be a snowman, it can be whatever you want, I'll let you choose!"  
Finally a response came, but not one that he would have hoped.  
"Go away Hiccup!" Eira shouted at him through the door.  
"Okay bye..." Hiccup whispered, trying not to let tears form in his eyes.  
Eira felt bad, but left the door and peered out her window.  
"Hic was right... This is beautiful..." She whispered to herself, placing her hands on the windowsill, to peer even closer out, however, it suddenly froze up, causing her to jump back in fear.  
Her powers used to be fun, but she never realised that they had the power to hurt or harm another, and it saddened her that she couldn't use them without fear any more. She couldn't trust them anymore.

A few weeks later, when Hiccup was in bed, Stoick came and unlocked Eira's door.  
"Eira, I have something for you, come with me." He said kindly, leading his nervous daughter out of her room.  
She took him to the drawing room, where there was a small fire burning. Stoick took one of her hands, and Eira instantly jumped back, knowing she couldn't control her powers and could very well freeze him.  
"The gloves will help, see." Stoick said simply, placing one glove on each hand and holding her gloved hand between two of his, Eira's face lit up a little.  
"Conceal it," Stoick started, repeating their small mantra.  
"Don't feel it," Eira continued.  
"Don't let it show." They finished together, smiling at each other.  
"Would you like me to read you a story?" Stoick asked Eira awkwardly.  
He wasn't really much of a story teller but he hardly spent any time with Eira any more.  
"No thank you Pappa, I'm very tired." She said softly, smiling. "Goodnight Pappa, and thank you."  
And with that, she walked back to her room, and locked herself in.

Years passed, without so much a hug, or any time together between Hiccup and Eira, they grew distant. Within the first year, after the snowman incident Hiccup was visiting her at least once a week, sitting on the other side of the door, telling her about his day, and how much he missed her, but he noticed her slowly getting more angry with the way she told him to go away, and so Hiccup realized that she wasn't too fond of the contact, and so cut down to a visit every month, and then a visit every two months, and by the time Hiccup was nine, he hadn't spoken to his sister in almost six months, but a few days after his birthday he decided he would try again. He knocked on the door in his usual rhythmic pattern  
"Do you wanna build a snowma-" He started but was cut off by Eira.  
"Hiccup it's not snowing."  
"Okay fine, do you want to come ride out bike with me then?" He tried.  
"Hiccup the gates are shut." She responded coldly.  
"Well we could always ride it around the halls?" He suggested.  
"Oh Hiccup please... Can you even ride a bike? You'll break something." She replied spitefully.  
"Eira I just think that we need to spend some time together..." He said sadly. "I think some company is overdue, I don't have any friends anymore."  
"You never had any anyway." The twelve year old sneered.  
"Well now the pictures are my friends Eira, they're the only people I can ever have a chance to speak to around here!" He said sarcastically.  
Silence.  
"It just, it gets a little lonely out here, all the empty rooms, hardly any people, just watching the hours tick by..." He said quietly, but received no response.

"PAPPA!" Came a scream from Eira's room.  
She sounded frightened, like she never had before, and that one word had been filled with so much fear, Hiccup hadn't even thought it possible. Stoick, of course, came running, and saw Hiccup wandering the corridors.  
"Get back to bed son, I doubt you'll want to see this." He said quietly.  
Hiccup nodded, scared, and scurried off to his room. Stoick, on the other hand, unlocked the door, and came in.  
"Eira what i- Oh Eira..." He said, scared himself.  
There was a big jagged patch of ice in the corner of her room.  
"I took the glove off for just a second Pappa! Just a second and look! I'm scared! It's getting stronger!" She cried.  
"Getting upset only makes it worse..." Stoick replied gruffly. "Just calm down."  
He went in to comfort her, but she jumped back.  
"No! Don't touch me! Please! I don't want to hurt you..." She replied sadly.  
Stoick just sighed, gave her a sympathetic look, and left the room.  
"I'm sorry Pappa..." She whispered

After that day, Hiccup began to visit his sister on only two days, on his birthday and on her birthday. He would never say much, just, if it were hers 'Happy Birthday, I wish I could see you and tell you properly.' and if it were his, 'It's my birthday today, the only present I want is to see you again.' but she never came out. The years passed, until Hiccup was fifteen and Eira was eighteen. He had still seen nothing of her. He wandered the halls, to see his father, just before he left for a two week conference with another region. He passed Eira's door, and sighed silently to himself.  
"Dad!" He called, causing the man to turn around and chuckle, giving his son a bear hug. "Bw- ak! Ca- an't br-reathe." He said, before his father let him go, smiling warmly. "See you in two weeks Dad."  
"You're becoming a fine prince Hiccup, don't let anyone tell you any different, now go and finish that book you were talking about at breakfast." He said with a proud smile.  
"I will Dad!" He said, jogging back to his room.  
After Hiccup's door had shut, Eira silently crept out of her room, and stood by the gates of the castle, waiting for her father. He came down the stairs, a servant hauling his luggage behind him, and Eira curtseyed to him.  
"Do you have to go?" She asked.  
"You'll be fine Eira." He said, pulling her into a hug. "Take care of yourself!"  
"You too!" She called in reply.

His trip was supposed to be two weeks, but it wasn't two days later that the telegram was sent.

_Dear our faithful royalty, Princess Eira and Prince Hiccup  
I regret greatly to have to inform you that the ship your father was on got caught in a vicious storm in the middle of the sea. The entire ship sank and there were no survivors. We have searched, but we have not managed to find anyone alive.  
I apologize greatly for your loss, and the entire kingdom is behind you._

Hiccup couldn't believe it, the only person, his only company, gone. He slipped the telegram under Eira's door silently, walking off.  
Eira couldn't believe it, the only person who knew, her only company, gone.

Eira did not attend the funeral. Her powers had grown so much greater and with the sudden grief, she found she could no longer control it, her room became a blizzard, a still cold field, an icy storm. She could not leave her room for fear of revealing it, but she could not tell Hiccup that. He begged her and pleaded her, with tears and promises, but she could not leave her room. By the sounds of it, he had grown up considerably and had indeed turned into an excellent Prince.

Hiccup came back from the funeral teary eyed and slumped himself against his sisters door and knocked regularly.  
"Look Eira... Please... I know you're in there, people were asking where you were today..." He began, and Eira looked up from her position, backed against her own door, her arms around her knees, her face stained with tears. "They tell me to have courage, and I'm trying to, I'm right out here, I know how you're feeling and I can help me... You just gotta let me in... We only have each other now and there's nothing we can do about it, so... Let's band together again! Let's-" He broke down in tears. "Eira what are we going to do..."  
"Do you wanna build a snowman?" He asked in desperation, banging the back of his head against the door.

**This was supposed to only be half a chapter but turns out I could write a lot for one song so this has become an independent chapter. Please review and I will definitely have the next chapter out soon.**


End file.
